1. Effects of LCF Loadings on the HCF Life of Notched Specimens in Ferritic-Bainitic Steel
- Author
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BIDOUARD, Hadrien, PALIN-LUC, Thierry, SAINTIER, Nicolas, KAUFMANN, Heinz, DUMAS, Christian, EL DSOKI, Chalid, and SONSINO, Cetin Morris
- Subjects
Materials science ,Overload ,Tension (physics) ,business.industry ,Mécanique [Sciences de l'ingénieur] ,Mechanical Engineering ,Stress–strain curve ,Low cycle fatigue ,Fatigue testing ,Structural engineering ,Fatigue limit ,Finite element method ,Shakedown ,Amplitude ,Mécanique: Génie mécanique [Sciences de l'ingénieur] ,Mechanics of Materials ,Variable Amplitude ,Cumulative damage ,Crack initiation ,General Materials Science ,Fatigue life ,Composite material ,business ,High cycle fatigue ,Load ratio - Abstract
Fatigue tests were performed on ferritic bainitic steel notched specimens (Kt = 2.5) under load controlled constant amplitude loading. These tests show that under constant amplitude tension compression loading, periodical overloads application have a detrimental effect on the fatigue crack initiation strength for fully reversed load ratio (Rσ = −1), while they have no influence under pulsating loading (Rσ = 0). A finite element analysis shows that in the fully reversed tension (Rσ = −1), the stabilized cyclic behaviour at the notch root is an elastic-plastic shakedown while elastic shakedown is obtained under pulsated regime (Rσ = 0), so that we can consider that the local cyclic behaviour has an influence on the overload effect. However, the overload application does not imply a remarkable modification of the stress and strain field under the subsequent constant amplitude loading and can not explain such a fatigue strength decrease in fully reversed tension.
- Published
- 2009